<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta http-equiv="X-UA-Compatible" content="ie=edge" />
    <title>后盾人</title>
  </head>
  <body></body>
  <script>
    let arr = [1, 2, 3, 4, 5];
    function includes(array, find) {
      for (const value of array) if (value === find) return true;
      return false;
    }
    console.log(includes(arr, 99));
  </script>
</html>
